package dujiu.luogu.sequence;

import java.util.Scanner;

public class P3954 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int A = scanner.nextInt();
        int B = scanner.nextInt();
        int C = scanner.nextInt();
        System.out.printf("%.0f",A*0.2+B*0.3+C*0.5);
    }
}
